This invention relates to an expandable, contractable and bendable arm.
In recent years, in nuclear reactors and many other industries, it has been desired to maintain, inspect and measure various parts from a remote place for avoiding danger of irradiation of radioactive substances, and for saving power.
To effect such remote operation, according to a prior art method, a manipulator or other operating device is mounted on a carriage which is controlled remotely and after bringing the carriage to a working place the manipulator is expanded or contracted to perform desired operation.
However, the carriage cannot approach an object beyond a limit because of the presence of obstacles in the working space. Moreover, as there is a limit for the length of the arm of the manipulator its workability is also limited. Further, prior art arms could not be contracted from the state in which the arm has been extended straightly, and cannot be bent.
One example of a manipulator arm which can be bent is disclosed in U.S.S.R. Inventor's Certificate No. 422580. The arm shown therein, however, cannot increase or decrease the length thereof.